Insulating compound



Patented June 29, 1926.

UNITED STATES 1m PATENT orrlcs.

CORNELIUS PICKSTONE, Q1 RAJJGLII'FE, ENGLAND.

msum'rme couromm.

Ilo Drawing. Application filed May 11, 1925, Serial Ho. 29,569 and in Great Britain July 81, 1924.

This invention has reference to a new composition, mixture, or compound of materials which is very useful as a substitute for porcelain, earthenware, ebonite, vulcamte or like insulating material employed for electrical work, but which composition can Y be applied to many other uses'or where a hard, smooth, strong an tive looking material is required.

The composition consists of a mixture of slate powder, rubber, bitumen and colourin matter along with a vulcanizing materia such as sulphur. The bitumen or the colour- .ing matter may be omitted as commercial results are obtainable for various purposes with the omission of either the bitumen or the colouring matter.

The amount of rubber incorporated would vary with the degree of hardness or resilience desired in the composit1on.

In the carrying out of my invention I urposes attrac- --make use of proportions preferably by.

' weight such as the followin slate powder 40 per cent to 7 0' r cent,.ru ber 15 per cent to 25 per cent, bltumen 2 per cent to 10 per cent, vulcanizing material and colouring matter 13 per cent to 25 per cent.

If'the bitumen be omitted then I would to per cent.

portionately increase the other items. 1 In reparing the com osition or mixture 1' utillzeslate waste an 'this' is round to 85 a very, finepowder or dust and t e rubber is also ground to. a meal or powder and the rubber ma be more or less purerubber or a mixture 0 pure rubber and re-claimed rub her. The bltumen where such is used is also ground tov a. powder as is the colouring matter which may be carbon black, coloured oxides, or other colouring ingredient oringredients using one, two or more colours.

The whole of the items are mixed to-- use the rubber in proportions of 17 per cent If colouring matter be omitted I may proinlays, -floor coverings and for t e tion of numerous articles. and particularly Following heating the bitumen altogether, or the colouring matter altogether.

The colouring matter when introduced may be such asto colour the mixing throughout the mass or in' patches or sections.

The results obtained have the ap arancel offinely surfaced ebonite'or the ike. and when colour matter is used of finely coloured ebonite. The material is a good insulating one, uniform in texture, not easily broken and capable of takin a high polish. The colouring matter pro uces very artistic effects and whenpthe colour is in sections amorphous designs or colour markings are The product can be drilled and itapped and worked with machine tools, sawn, cut, surface ground and she, ed with emery or carborun'dum wheels, an its uses for insulation and other purposes are innumerable. The composition can be used' for' utensils,

vases, ornaments, lamp holders pedestals,

when various colours are introduced.

I declarethat what I claim is:-

1. Aninsulating composition comprising slate powder approximately. 40 to- 0 per cent, rubber from 15 to 25 per cent, pitch from 2 to 10 per cent, vulcanlzing material including coloring matter from 13 to 25 per cent.

2; An ins latinsg comp m l finely powdered to in the proportion o 40 to 7 0 per. cent,'powd ered rubber from 15 to 25 percent, powdered bitumen representing 2 to 10 per cent, and a mixture of powdered colori matter and vulcanizin'g material representing from .13 t0'25 per cent,

the ingredients being heated, the .vulcaniz 1ng material added and the result moulded,

roducpressed, and cured by heat, all as set forth.-

In testimc ny whereof I have signed my name to this specification. I

. CORNELIUS PICKSTONE 

